M82 is a galaxy that's relatively near to the Milky Way. It's not in our own local group, but it's in a nearby group of galaxies (the "M81 group"), and is only about 12 million light-years away (which is close for a galaxy). It's notable because it's a "starburst" galaxy— it's undergoing a burst of rapid star-formation, producing large numbers of stars in big clusters in a relatively short period of time. A lot of this activity is near the nucleus of the galaxy.
M82 is a favorite target for infrared astronomers. My cohort in graduate school, James Larkin, wrote his first grad school paper on the galaxy; both of us were part of what was known as the IRA, or "InfraRed Army," at Caltech.
The image below was taken with the Hubble Space Telescope. You can see the disk of the galaxy, but it's clear that there's some action going on at the center, buried behind thick dust. The plumes coming out of the center are mostly Hydrogen gas which has been blown out of the galaxy by shocks from supernova explosions; such explosions are much more common in M81 than in our own galaxy (where we only have about one every hundred years or so) because of the rate at which stars (including the massive, short-lived stars that eventually supernova) are being made.